private void ExecuteForeignPredicate(AbstractMachineState state)
{
Assembly loadedAssembly = Assembly.LoadFrom(_assemblyName);
Type[] types = loadedAssembly.GetTypes();
AMForeignPredicate fp = state.GetForeignPredicate(_predicateName);
if (fp == null)
{
throw new Exception("INTERNAL ERROR: cannot find foreign predicate " + _predicateName);
}
foreach (Type type in types)
{
if (type.Name == _classType)
{
foreach (MethodInfo mi in type.GetMethods())
{
if (mi.Name == _methodName)
{
if (mi.ReturnType == typeof(bool))
{
fp.ReturnType = AMForeignPredicate.R_BOOL;
}
else
{
fp.ReturnType = AMForeignPredicate.R_VOID;
}
bool foreignMethodResult = InvokeForeignPredicate(type, mi, fp, loadedAssembly, state);
// bool, fail = !foreignMethodResult (if fail, backtrack, else P++)
// internal, (if fail, backtrack, else P++)
// void, if fail backtrack, else P++
if (fp.ReturnType == AMForeignPredicate.R_BOOL)
{
state.Fail = !foreignMethodResult;
}
else if (fp.ReturnType == AMForeignPredicate.R_VOID)
{
((AMProgram)state.Program).Next();
return;
}
if (state.Fail)
{
state.Backtrack();
}
else
{
((AMProgram)state.Program).Next();
}
}
}
}
}
}
private bool InvokePredicate(Type type, MethodInfo methodInfo, AMForeignPredicate fp, AbstractMachineState state, Assembly loadedAssembly, ArrayList methodArguments)
{
object[] arguments = methodArguments.ToArray();
object returnedResult = null;
object baseObject = null;
baseObject = Activator.CreateInstance(type);
returnedResult = type.InvokeMember(_methodName,
BindingFlags.Default | BindingFlags.InvokeMethod,
null,
baseObject,
arguments);
int registerIndex = 0;
foreach (AMForeignPredicateArgument fArgument in fp.Arguments)
{
if (fArgument.PassingType == AMForeignPredicateArgument.PASS_OUT ||
fArgument.PassingType == AMForeignPredicateArgument.PASS_INOUT)
{
AbstractTerm term = ((AbstractTerm)state["X" + registerIndex.ToString()]).Dereference();
if (fArgument.Type == AMForeignPredicateArgument.T_TERM)
{
ConstantTerm argumentVariable = new ConstantTerm(arguments[registerIndex]);
term.Assign(argumentVariable);
}
else
{
if (fArgument.Type == AMForeignPredicateArgument.T_STRING)
{
if (term.IsReference)
{
term.Assign(new ConstantTerm(arguments[registerIndex]));
}
}
}
registerIndex++;
}
}
bool returnValue = false;
if (fp.ReturnType == AMForeignPredicate.R_BOOL)
{
if (returnedResult == null)
{
return(true);
}
else
{
returnValue = (bool)returnedResult;
}
}
return(returnValue);
}
private bool InvokeForeignPredicate(Type type, MethodInfo methodInfo, AMForeignPredicate fp, Assembly loadedAssembly, AbstractMachineState state)
{
int registerIndex = 0;
ArrayList methodArguments = new ArrayList();
foreach (AMForeignPredicateArgument arg in fp.Arguments)
{
AbstractTerm term = ((AbstractTerm)state["X" + registerIndex.ToString()]).Dereference();
switch (arg.Type)
{
case AMForeignPredicateArgument.T_BOOL:
bool bResult = false;
if (!Boolean.TryParse(term.Data().ToString(), out bResult))
{
return(false);
}
methodArguments.Add(System.Boolean.Parse(term.Data().ToString()));
break;
case AMForeignPredicateArgument.T_CHAR:
if (term.Data() == null)
{
return(false);
}
methodArguments.Add(Convert.ToChar(term.Data()));
break;
case AMForeignPredicateArgument.T_DOUBLE:
case AMForeignPredicateArgument.T_FLOAT:
case AMForeignPredicateArgument.T_INTEGER:
int iResult = 0;
if (!Int32.TryParse(term.Data().ToString(), out iResult))
{
return(false);
}
methodArguments.Add(Int32.Parse(term.Data().ToString()));
break;
case AMForeignPredicateArgument.T_STRING:
methodArguments.Add(term.Data().ToString());
break;
case AMForeignPredicateArgument.T_TERM:
methodArguments.Add(term);
break;
}
registerIndex++;
}
return(InvokePredicate(type, methodInfo, fp, state, loadedAssembly, methodArguments));
}
private bool InvokePredicate(Type type, MethodInfo methodInfo, AMForeignPredicate fp, AbstractMachineState state, Assembly loadedAssembly, ArrayList methodArguments)
{
object[] arguments = methodArguments.ToArray();
object returnedResult = null;
object baseObject = null;
baseObject = Activator.CreateInstance(type);
returnedResult = type.InvokeMember(_methodName,
BindingFlags.Default | BindingFlags.InvokeMethod,
null,
baseObject,
arguments);
int registerIndex = 0;
foreach (AMForeignPredicateArgument fArgument in fp.Arguments)
{
if (fArgument.PassingType == AMForeignPredicateArgument.PASS_OUT ||
fArgument.PassingType == AMForeignPredicateArgument.PASS_INOUT)
{
AbstractTerm term = ((AbstractTerm)state["X" + registerIndex.ToString()]).Dereference();
if (fArgument.Type == AMForeignPredicateArgument.T_TERM)
{
ConstantTerm argumentVariable = new ConstantTerm(arguments[registerIndex]);
term.Assign(argumentVariable);
}
else
{
if (fArgument.Type == AMForeignPredicateArgument.T_STRING)
{
if (term.IsReference)
{
term.Assign(new ConstantTerm(arguments[registerIndex]));
}
}
}
registerIndex++;
}
}
bool returnValue = false;
if (fp.ReturnType == AMForeignPredicate.R_BOOL)
{
if (returnedResult == null)
{
return true;
}
else
{
returnValue = (bool)returnedResult;
}
}
return returnValue;
}
private bool InvokeForeignPredicate(Type type, MethodInfo methodInfo, AMForeignPredicate fp, Assembly loadedAssembly, AbstractMachineState state)
{
int registerIndex = 0;
ArrayList methodArguments = new ArrayList();
foreach (AMForeignPredicateArgument arg in fp.Arguments)
{
AbstractTerm term = ((AbstractTerm)state["X" + registerIndex.ToString()]).Dereference();
switch (arg.Type)
{
case AMForeignPredicateArgument.T_BOOL:
bool bResult = false;
if (!Boolean.TryParse(term.Data().ToString(), out bResult))
{
return false;
}
methodArguments.Add(System.Boolean.Parse(term.Data().ToString()));
break;
case AMForeignPredicateArgument.T_CHAR:
if (term.Data() == null)
{
return false;
}
methodArguments.Add(Convert.ToChar(term.Data()));
break;
case AMForeignPredicateArgument.T_DOUBLE:
case AMForeignPredicateArgument.T_FLOAT:
case AMForeignPredicateArgument.T_INTEGER:
int iResult = 0;
if (!Int32.TryParse(term.Data().ToString(), out iResult))
{
return false;
}
methodArguments.Add(Int32.Parse(term.Data().ToString()));
break;
case AMForeignPredicateArgument.T_STRING:
methodArguments.Add(term.Data().ToString());
break;
case AMForeignPredicateArgument.T_TERM:
methodArguments.Add(term);
break;
}
registerIndex++;
}
return InvokePredicate(type, methodInfo, fp, state, loadedAssembly, methodArguments);
}
